Physics 121 General Physics
Concept Quizzes
Chapter 5. The Laws of Motion

A Net Force F acts on an object.

1. This means that

	the object must be moving in the direction of F.
	the object may be moving in any direction.

2. This also means that

	the object must be accelerating in the direction of F.
	the object could be accelerating in any direction.

Consider a person standing in an elevator that is accelerating downward. The magnitude of the upward normal force exerted by the elevator floor on the person is

	larger than
	smaller than
	equal to

the magnitude of the weight of the person.

A small sports car collides head-on with a massive truck.

1. Which vehicle experiences the greater magnitude force during the collision?

	The car.
	The truck.
	The answer depends on the speeds the vehicles were moving.
	Both experience the same force during the collision.

2. Which vehicle experiences the greater magnitude acceleration during the collision?

	The car.
	The truck.
	The answer depends on the speeds the vehicles were moving.
	Both experience the same acceleration during the collision.

A box is sliding down a ramp. It is accelerating. What would be the Free Body Diagram of the forces on the box?

A mass, m, is pushed with a horizontal force, F, on a horizontal surface. The coefficient of static friction is μ_s. The block does not move. The magnitude of the static friction force on the mass is

	μsmg
	μsF
	F
	mg